Many people maintained their faith in Lance Armstrong for a long time, and faithful Linus van Pelt is still waiting for the Great Pumpkin to return. I'm sure Borislav Ivanov has his defenders too - though I bet they haven't had to play him in a tournament with money or norms on the line. Anyway, it seems he has unretired for the moment, and readers can catch up on his most recent adventures here and here.
(HT: Nate.)